Motor-driven switching mechanism



Patented May 9, 1950 UNITED STATES ?ATENT OFFICE John F. Toomey, Floral Park, N. Y., and Ralph L. Cordell, Tulsa, Okla.

Application June 18, 1947, Serial No. 755,274

(Granted under the act of March 3, 1883, as amended April 3U, 1928; 370 O. G. 757) 5 Claims.

This invention relates to a switching mecha-k nism and more particularly to a motor driven switching mechanism in which the switching elements are sufficiently rugged to withstand severe shock without false operation and in which the ently not well adapted to withstand the impact 2 of a blow or sudden-acceleration or deceleration without injury or false operation of the contacts. The device of the present invention possesses y all of the advantages of the prior devices and none of the foregoing disadvantages by reason of the novel arrangement of parts and structure as will appear more clearly as the description proceeds.

The operation of the device of the present invention differs from the principle of operation of the prior devices principally in the means employed for operating the switching contacts and in the rugged construction and stacked arrangement of the leaf spring switching contacts whereby operation of the `switching contacts is prevented in response to shocks received by the device.

In accordance with a preferred embodiment of the invention the contacts are actuated to the operated position thereof by a rotatable member in threaded engagement with a nonrotatable member whereby axial movement of the nonrotatable member sufficient to actuate the contacts is effected by the operation of an electric. .y motor in response to a momentary now of operating Ycurrent thereto. The threaded members maintain the contacts in an operated position until the motor is reversed by a momentary flow of current in the opposite direction through the motor. A rugged structure is thus provided which is well adapted to fulfill the objects of the invention and withstand severe shocks and sharp changes in acceleration or deceleration without false operation of the contacts.

l `The device is particularly adapted for use with ordnance devices which are subject to violent shocks or changes in acceleration or deceleration such. for example, as assault boats of the type claimed in the copending application for Demoli- 2 tion system of E. M. Brown et al., Serial No. 584,996, led March 26, 1945.

One of the objects of the invention is to provide a new and improved self-locking switching mechanism which is sufficiently rugged to withstand severe shocks and changes in acceleration or deceleration without false operation of the contacts or injury thereto.

Another object is to provide a motor driven switching mechanism adapted to close and lock a plurality of switching elements in response to a momentary flow of current through the motor.

Still another object is to provide a new and improved motor driven switching mechanism adapted to close a plurality of control circuits in response to a momentary flow of current through the motor and maintain the contacts closed until the motor receives a momentary iiow of current in the opposite direction.

Still other objects, advantages and improvements will be apparent from the following description, taken in connection with the accompanying drawing, of which:

Fig. l is a circuit diagram of the complete device according to a preferred embodiment thereof and Fig. 2 is a View in elevation of an alternative form of the device.

Referring now to the drawing for a more complete understanding of the invention on which like numerals of reference are employed to designate like parts, and more particularly of Fig. 1 thereof there is shown thereon a complete switching mechanism and control circuits therefor adapted to close a pluruality of external control circuits as the mechanism operates in response to a momentary flow of current through the motor M. The motor is of the direct current reversible type such, for example, as the type disclosed in the aforesaid application of E. M. Brown et al. for Demolition system in which the motor eld is obtained from a permanent magnet and the direction of rotation of the motor is controlled by the polarity oi the voltage applied thereto.

The motor is provided with a shaft extension 9 threadedly in engagement with a member l0 adapted to be moved axially in either direction along the shaft selectively in accordance with the direction of rotation of the motor. The member Hl is, of course, restrained from rotative movement in any well known manner during rotation of the shaft as by the pin H along which the member I0 is adapted to move. The member ID is thus adapted to be moved into engagement with a follower l2 when the motor has been set Y may be subjected to severe shocks such, for example, as those caused by demolition?andfcoun-- termining explosions, the spring leaf contactsare@ constructed of suiiicient ruggedness and stiffness*- to prevent operation thereof in response to'such shocks. By reason of the great mechanical-adv vantage of the motor driven screw driveor the contacts, however, the motor' requires onlya sm'all` amount of energy to actuate the contacts not` `withstanding the requirement that the contacts besuflicieritlylruggedf to'Y prevent' false operation thereof.- Y

Themotor control c'ircuitpreferably includes a startinglrelay'R adapted to be operated in rei sporise to theclosureof a starting circuit at the switch I'I thereof associated with the starting element I8: The motor` control circuit also includes a relay RI adapted t`o"be` operated'in re:` sp'on'setothe closure of switch I9 within a controlelement 2l and tliereby. cause 'a' momentary oW" of current in' a reverse direction to the motor sufficient to operate the motor reversely aridrestorethe switching mechanism to the origiiial unoperatedcondition.

,The operation of the device wil'lbest be un-v derstood by consideration of an' assumed ex"- arnple; Let it (be assumed; by'way of example, that" tl'ieswitching `mechanisn`r ofl Fig.' l' is em'- ployed to control'the arming circuitof the afore-v said 'patent' application* for Demolition system of M Brown' et al. and thatv the switch I'I of the` starting element IB" isa'dapted to be closed" inrresponse to a signalrec'eivedfrom'a control* station' (not shown). Let' it further beassumed tlat'the' switching 'mechanism' is inthe normal unoperated position illustrated on the drawing' and that the Aassaultl boat is about to attackJ the target. The closure of switch*II-inresponse-toA a;A signal' from the control station closes the startingcircuitmfrom battery BA by way of con 50- du'ctor`22", switchA I'I, conductor-23 winding of" relay RiA conductor 24, contacts` I 6 of `the switchf ig" mecl'lanismjandV thence yby way of conductor' Zito-ground therebycausing relayR" to oper-- at'e." AS relay' Pcoperates;a'circuitisclosed from- 55 the positive terminal of battery BAI; conductor' 26V,l makeA contact and' armature 2T of relay R), conductor 28, winding of motor" M'," conductor" 291, armature 3| and make contact of relay R and thence byv way of conductor 32 to the 60 ofthe'motor M. The motor" now comes to 70 rest with theelement I0 thereof maintained outwardly by' reason Vof the threaded engagement thereof' with the shaft Il` thereby locking theA switching contacts in an operatedposition. As

of conductors 33 to the firing control apparatus and, in like manner, the closure of contacts I5 closes a circuit by way of the conductors 34 to the firing control apparatus. The conductors 33 and 34 may be conveniently employed to control the.V armingof a firing', circuit -as the contacts I 4 andi I Eirespectively associatedtherewith are closed.

The ring control apparatus may be of any Well knownV type suitable for the purpose in which the firingis accomplished by closing a circuitfromfa source of electrical potential to anlfele'ctroresponsive detonator thereby to fire a. mainexplosive charge (not shown). This is usually/'accomplished over a direct circuit from thepsourcea of potential to the detonator or, if desired, an amplifying unit may be employed to "increase:tlrestrength of the ring signal and thereby'i'lrethe detonator in response to a signal of relatively weak strength received by the firing control i apparatus: in which lattercase -contacts I4 :andi I 5may b'e ,employe'dft close vcircuitsV from f the`V Ai and B f batteries tothe*- amplifying unit;` Still-another'satisfactoryp5 arrangement is to em` ploy the sWitch'ingj rneclianis'my offthe 4 present: v`

invention for controlling the-'starting-andoperw ation of an electrically wound arming clock such, fonexample,l asftlie' arming Y clock disclosed and claimed in the"copendinig-y application of'l` theclock is"wo,und"at' regula-r intervals periodi'- callyby an electric motor, it beingmerely neces:-n

saryto includefthecontrolcontacts I4 or` I5; as the caseL may be, in the operating circuit off the-L motor- Obviously" withY this arrangement, thearming'clck-fWillnotfbe-set into operation until thecontrolcircuits thereto are closed'by the :switchingm'eclfi'aris'm-v of-fFigL 1.

The switching-l mechanism may Abe restoredl toI the ini-tial'V unoperated condition as shown onv Fig. 1 at any time desired such, for example,` as, just prior.l to.` setting:Y thee4 assault: boat" of the foregoing examplef intel" operation, Vby operating the switch' I 9 of tliezcontrolelement"A 2 I. Let: it; nowbef assumedzforzftlref purpose-1 of: descriptionI that: the .switching mechanism.; is in the operated position and-i itrisrd'esired-:trestore it f to an i initial `unoperatedposition.v The# closure .Y of switch |91: applies.batteryv BAZto conductor 35, .winding of relay RI, conductor 36, contacts I3 of the;v switching.:` mechanism., from whence the circuit is/contin-uecll by.. way` ofl conductor 25.. to ground thereby.y causingfrelay RI topperate.-A The op.- eration orfA relay RI. closesa.circuit.l from thel positive. terminalfrom. battery BAI by way, of.. conductor 26, malr'encvzmtactr anda-rmaturefl. of.. relay RI., conductor2l9, windingeof. the motor. M; conductor., 2.81 `armature 38.r andmake contactn of.relayA RI- andthencerby wayv of-.conductor 32V to ground.' thereby ca1'1sing ..current to. flowA througHthe'motor M andfoperate the motor., in a direction to' withdrawl the member IIlin'wardly. with respect thereto. As Vcontacts I3; are disengaged during the"v inward travel of, the .member IIL., the circuit" tof relayA RIl is.V interrupted and relayflftl relases armatures 31 and 38" of` relay R'I i are* moved' sufliciently to disengage their respective contacts,itlre operating circuit" tothe motor M"` is` interrupted 'andthe' motor M comes: to` rest" with the"q member I0 thereof fully'l retracted The switching; mechanism isV now* restored to'l its: originali unoperated condition contacts; I4 areengaged,v acircuit is closed by way 75 withcontacts.;v 1IS7:tliereoff'closedand"the opera-ting circuit of relay R in readiness to be energized by switch Il of the starting element I 8.

On Fig. 2 is shown an alternative form of the switch operating mechanism in which the motor M is arranged to make a predetermined number' of' free revolutions before the load is applied thereto. This is accomplished by extending the shaft 39 thereof and providing the end portion of the shaft with a spindle bearing 4l having' a member 42 arranged for free rotation with respect thereto, means being provided for preventing endwise movement of the member 42 `with respect to the shaft. The member 42 is provided with a threaded portion 43 in engagement with a complimentary threaded portion in the member 44. The member 44, it will be understood, is provided with any well known means for preventing rotative movement thereof while permitting axial movement in either direction in response to selective rotation of the member 42. The member 44 is adapted to close the spring assemblies of Fig. 1 in a similar manner to the member It of Fig. l.

There is secured to the shaft v39 as by the pin 45 a member 46 having a pin 41 projecting therefrom substantially as shown. A washer 48 is mounted for rotation with respect to the shaft 39 intermediate the members 46 and 42 and provided with a pair of pins 49 and 5! disposed on opposite sides thereof and adapted to be engaged respectively by the pin 4l and a pin 52 arranged on the member 42.

When the motor has made substantially one revolution, the pin 4l is moved into engagement with pin 49 thereby causing the washer 48 to rotate. When the motor has made substantially one additional revolution the pin 5I of the washer 48 is brought into engagement with pin 52 thereby causing the member 42 to rotate. This arrangement may be defined herein as an acceleration drive in which the motor is permitted to make several revolutions before the load at the member 42 is applied thereto. This arrangement permits the use of a smaller motor than the arrangement of Fig. l and, if desired, may be employed in lieu of the motor arrangement of Fig. 1 for operating the switching elements of the device. Whereas in Fig. 2 a single free washer 48 has been illustrated, it will be understood that, if desired, additional washers may be employed whereby the motor may make several additional revolutions before the load is applied thereto.

The spring members I2, I3, I4, I5 and I6 are of strong low compliance construction and sufficiently rigid to withstand a severe shock or sudden change in acceleration or deceleration without falsely operating any of the contacts of the device and thus the device is reliable in operation even though the assault boat should be severely jolted by enemy fire while on its mission.

The device of the present invention may, if desired, also be used to arm or sterilize, as the case may be, mines, depth charges and the like, it merely being necessary to close the starting circuit to the relay R by any suitable means such, for example, as by a hydrostat, time clock or the like.

The switching mechanism may, if desired, be made slow operating whereby a predetermined time delay is effected between the closure of the motor operating circuit and the operation of the switching contacts. This may be accomplished in any suitable manner as by employing a reduction gearing between the motor and the member Il or 46, as the case may be. Furthermore,

0 the motor may be employed to open a plurality of normally closed contacts or any combination of normally closed and normally open contacts during the operation of the device.

While the invention has been described with reference to two examples thereof which give satisfactory results, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, in the appended claims to coverall such changes and modifications.

The invention herein described and claimedmay be .manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a switching mechanism of the character disclosed comprising a plurality of switching elements adapted to close a plurality of control circuits individual thereto, a reversible motor, means including an acceleration drive connected to said motor for operating said switching elements selectively in accordance with the direction of rotation of the motor as the motor operates, said acceleration drive comprising a driving member secured to the shaft of the motor, ya driven member rotatively carried on said shaft, an actuating member threadedly carried on said driven member, means for preventing rotation of the actuating member whereby the actuating member is moved axially as the driven member operates, means for establishing a driving connection between said driving and driven members when the motor has made a predetermined number of free revolutions from an initial position of rest, and means controlled by one of said switching elements for causing a momentary iiow .of current in said motor sufficient to operate the switching elements.

2. A shock-proof switching mechanism of the character disclosed comprising a reversible motor having a threaded shaft, a member in threaded engagement with said shaft and having an eccentric bore therethrough arranged parallel to said shaft, a pin slidably arranged within the bore of said member and in xed parallel relation with respect to said shaft whereby said member is moved in either direction along said shaft selectively in accordance with the direction of rotation of said motor, and a stack of strong low compliance leaf spring switching elements of sufficient rigidity to withstand countermine shocks received by the mechanism for preventing false operation thereof and supported in the path of travel of said member and adapted to be moved thereby into circuit controlling relation selectively in accordance with the direction of movement of said member along said shaft.

3. In a demolition system, a shock-proof switching mechanism of the character disclosed comprising a reversible motor having a threaded drive shaft, a member in threaded engagement with said shaft for movement along the axis thereof selectively in accordance with the direction of rotation of the motor when the motor is operated, a plurality of strong low compliance leaf spring switching elements of suicient rigidity to withstand severe shocks for preventing false operation thereof and supported in spaced relation to each other and in the path of travel of the member for operation thereby selectively in emessi@ aeecrdmcewithfmefdirectionalmqvememrof;the; memberrlailongsthe axis: of ithey motonshaftaszthev motrsoperetes, andfmeansfs-for; ceasing-esaid:moi4

tor to operate selectiveiyrineither.:directione` 4;,-.Iz`1;-.aatdemoiition'.t system,l 2,'. shock-proof injdividua1--. to'`V saidrcontrol 1 circuits and: of suflicitanteV rigidity; tog. withstand;` severeishocks forl preventing-:falsefoperation.. thereof and supported.; ingpredeterminedfspaced :relation A',With, respectto f; each other and transversely-,110isaidmembeninthe@l path or,` movementulthereof; wherebyf the switching;elementsaare operated -by.. thej memberselectively in.;A accordance; with: the; direction of moyementhoffthe. member as the,motor operates,= and;meansv for operating the motor selectively in etti; direction.V

5@ A:y:311901@proof;mechanism of the .character diseiosedqcomprising; in combination, ,a reversible mot -`hrgtving ashet,; am.v aceleration drive vcomse ndQmeniber.rotattively"supportedv on the shaft ondlmemberufrom the motor, and aiV third 'member first inernicer securedfto the Y shaft end; u an. eccentricaily, disposed armextencledY therefrom.. paralleli: to. theaxis of the shaft, 2...,

n evirig anpeirY ofeccentricaliy disposed arms. :gtendedtherefrom on eitherv side thereof Vand, parallelto .the axis lof Athe shaft, onecof the .armsQk ofrfsaidgsecondmember being extended intovth'e pethof trayelfof thearmof said rst member. sol q beY engaged thereby as the iirst member rgtetfeswith the shaft thereby to drive the see-- V berief revolutions from.raninital@startinggpoe rotatively supported-on .theesheftfrend havingexrl; eccentricalty f disposedgfarm extended;v therefrom; parallel; to, the exist, off the shaftl and :into the path `of .travelfioflthe other .oneoi theg-.armstofri-the-, second member,sorgasvvtolbeengaged-t they-second member;rotatesfthereby? thirdmember.frQm-themotor.:said third memb having?. threadecrfsheftlseured thereto, armeni A ben i supported; by; and;l threededi-y engaged .iwi'tktr Said threaded-Shaftrand adapted ltQ-Irmve axielin withrespectgtherfetodurnesrotatien,-Ofithefth di member-:in eitherfdiretion selec-.tively i accer ance. .with theidirection of .rotation;off:the ,etere when the motorhas-megdeapredetlmined nu tion',fandr e *stack ofi/strong 1ow-.- comp1iance;v1e spring-f c ontects` Y of sufficient.; rigidityfto prei/e opertion thereof"v in responsefzto -shocksgreceiv fr by.y the Yrnecharnisxn 4 and Y arranged -in the,pt of; travel of: said threededly engagedmgemheres ai; tofbe operated thereby :selectively `gin accordance;

Vwith ther direction of movei'ijient thereov 

